<table border="0" cellpadding="2" cellspacing="0" width="100%">
<tr>
<td><H2><font color="#336699" class="PageHeader">Different Resource Management Strategies with Grid Engine</font></H2></td>
</tr>
</table>
<table border="0" cellpadding="2" cellspacing="0" width="100%">
<tr>
<td>

<br><br>
This HOWTO discusses the PROs and CONs of different approaches
for managing resources. It originates from a response to the
question &quot;How can I minimize the delay of a load sensor tracking
software licenses?&quot; asked in the <A HREF="http://supportforum.sun.com/gridengine/">Sun
SupportForum</A>. The answer was:</P>
<P>It's quite natural that <A HREF="/project/gridengine/howto/loadsensor.html">load sensors</A>
have a delay. It can't be prevented and for this reason using load
sensors is only the 3<SUP>rd</SUP> best approach to manage license
consumption.</P>
<UL>
	<LI><P>The best way for managing licenses is the use of <A HREF="/project/gridengine/howto/consumable.html">consumable
	resources</A> (CR). Floating licenses can easily be managed with a
	global CR. Node-locked licenses can be managed in an analogous
	fashion. If you don't consider interactive use of your licenses you
	usually need only CRs and don't have to bother about load sensors
	delay.</P>
</UL>
<UL>
	<LI><P>If you need the licenses also for your interactive jobs we
	suggest the use of</P>
</UL>
<UL>
	<P>qrsh &lt;resource_request&gt; appl</P>
	<P>to achieve also interactive license consumption being gathered by
	Grid Engine. To make the use of qrsh invisible for your users the
	qrsh command can be either put in a script wrapper behaving like the
	original application, or you can use qtcsh to achieve
	transparency.</P>
</UL>
<UL>
	<LI><P>If it is not practicable for you to start interactive
	license-bound jobs through Grid Engine you can use the
	consumable resource setup as described above in combination with
	your load sensor for the same resource attribute. Grid Engine uses
	both information sources and does its best to derive from this how
	much of the resource is really available. Unfortunately, due to the
	loadsensor's delay, it can't be 100% excluded that batch
	jobs are dispatched and started although the license has been aquired
	by an interactive job. In this situation, however, batch jobs can react
	by explicitly triggering a rerun returning 99 as an
	exit status (collision detection). Load correction can sometimes
	help to reduce the number of reruns but it is only a solution, if
	you have an almost homogenous job profile.</P>
</UL>
<P>
</table>
